Patent Application
20110177574
The invention relates to a method for processing waste containing fermentable raw materials selected from sugars and raw materials such as starch and cellulose capable of being saccharified into fermentable sugars as defined in the preamble of independent claim 1.
The invention also relates to an apparatus for processing waste containing fermentable raw materials selected from sugars and raw materials such as starch and cellulose capable of being saccharified into fermentable sugars as defined in the preamble of independent claim 40.
The invention also relates to the use of the method or the apparatus for the production of ethanol from municipal biodegradable waste.
The invention relates to processing waste containing fermentable raw material selected from sugars and raw materials such as starch and cellulose capable of being saccharified into fermentable sugars.
The invention relates especially, but not excluding other types of waste containing fermentable raw material selected from sugars and raw materials such as starch and cellulose capable of being saccharified into fermentable sugar, to processing of municipal biodegradable waste. By municipal biodegradable waste is meant municipal biodegradable waste containing biodegradable waste, which means that the (so-called) municipal biodegradable waste to be processed by the method and apparatus need not to be entirely biodegradable and that the municipal biodegradable waste to be processed by the method and the apparatus can contain liquid matter and that the municipal biodegradable waste to be processed by the method and apparatus can contain non-biodegradable objects.
Nowadays municipal waste is sorted by the producer into several categories, one of which is municipal biodegradable waste including for example food waste and other similar biodegradable organic matter. The municipal biodegradable waste is normally placed by the producer in special waste bins for biodegradable material. Thereafter the municipal biodegradable waste is collected from the special waste bins and transported to processing facilities for processing. Known biodegradable waste processing methods are composting, biodegradation and burning. Composting means shortly aerobic decomposition of biodegradable waste to produce compost. In biodegrading the municipal biodegradable waste is broken down by the enzymes produced by living organisms.
Municipal biodegradable waste can in addition be used as a raw material for the production of biofuels. According to a research conducted by VTT (Technical Research Centre of Finland) 25 to 30 w % of the biodegradable waste in Finland is dry matter, the remaining 70 to 75 w % is liquid. Total carbohydrate content is about 40% of the dry matter, about 20% of the dry matter is starch, and about 10% ash. The rest is proteins, lignins and lipids WO 99/06133 presents a process for the production of ethanol and solid biofuel from municipal waste and other cellulosic feedstock.
Publication WO 2007/036795 discloses a process for production of fermentation products, including bioethanol by non-pressurised pre-treatment, enzymatic hydrolysis and fermentation of waste fractions containing mono- and/or polysaccharides, having a relatively high dry matter content. The process in its entirety, i.e. from non-pressurised pre-treatment over enzymatic hydrolysis and fermentation to sorting of fermentable and non-fermentable solids can be processed at a relatively high dry matter content in a single vessel or similar device using free fall mixing for the mechanical processing of the waste fraction.
Publication U.S. Pat. No. 5,677,154 discloses a method and an apparatus for the production of ethanol from non-virgin biomass having deleterious materials therein is provided. The deleterious materials prevent or retard the production of ethanol when the non-virgin biomass is combined with a fermentation material. The method includes primary processing, secondary processing and/or blending the non-virgin biomass with virgin biomass such that the effect of the deleterious materials is reduced, thereby allowing production of ethanol when the biomass is combined with the fermentation material.
Publication JP 2007097422 (A) discloses a system for fermentation, distillation and drying that is equipped with one closed type fermentation and drying tank, a suction pump for sucking gas in the closed type fermentation and drying tank and depressurizing the tank and an evaporator which communicates with the closed type fermentation and drying tank and condenses gases produced in treatment processes of water adjustment, saccharification, solid fermentation, distillation and drying of an organic substance stored in the closed type fermentation and drying tank and converting the gases to a liquid.
The object of the invention is to provide a new and inventive simple method and apparatus for processing waste.
The method of the invention for processing waste is characterized by the definitions of independent claim 1.
Preferred embodiments of the method are defined in the dependent claims 2 to 39.
The apparatus of the invention for processing waste is correspondingly characterized by the definitions of independent claim 40.
Preferred embodiments of the apparatus are defined in the dependent claims 41 to 68.
The invention also relates to the use of the method or the apparatus for the production of ethanol from municipal biodegradable waste.
In the invention the waste containing fermentable raw material selected from sugars and raw materials such as starch and cellulose capable of being saccharified into fermentable sugars is at least partly crushed to produce fine-divided waste of the waste. Said fine-divided waste is thereafter at least partly saccharified with saccharifying enzymes to break down starch and/or cellulose of the fine-divided waste to produce saccharified fine-divided waste containing fermentable sugars. Said saccharified fine-divided waste containing fermentable sugars is thereafter at least partly fermented with ethanol-producing microbes such as yeast to produce fermented fine-divided waste containing a mixture of ethanol and water. Said fermented fine-divided waste containing fermentable sugars and mixture of ethanol and water is thereafter at least partly dehydrated in an vaporization and dehydrating means for at least partly separating by evaporation said mixture of ethanol and water from said fermented fine-divided waste and for dehydrating said fermented fine-divided waste to produce dry matter of the fermented fine-divided waste. Said evaporated mixture of ethanol and water and said dry matter are thereafter discharged from said vaporization and dehydrating means.
The invention may comprise feeding partly dehydrated fermented fine-divided waste (partly evaporated sludge formed) from said vaporization and dehydrating means back to the fermentation means For example in situations of fermentation inhibition in the fermentation vessel, caused by high ethanol concentration or high organic acid concentration (e.g. lactic acid and acetic acid) or other fermentation inhibitors, it is possible to feed fermented fine-divided waste from the fermentation vessel to the vaporization and dehydrating vessel to perform a pre-vaporization step in which for a certain period of time excess volatile inhibiting compounds, such as ethanol, lactic acid and acetic acid, is evaporated off fermented fine-divided waste with the vaporization and dehydrating vessel, after which partly evaporated fermented fine-divided waste that has a reduced amount of fermentation inhibitors is fed back to the fermentation vessel for further or additional fermentation of the partly evaporated fermented fine-divided waste, resulting in higher yield and fermentation rate.
The fermentation step of the method of the invention may for example comprise a pre-vaporization step for removing fermentation inhibitors from fermented fine-divided waste containing fermentation inhibitors by vaporization fermentation inhibitors from said fermented fine-divided waste containing fermentation inhibitors.
The fermentation step of the method of the invention may for example comprise a pre-vaporization step which includes feeding step for firstly feeding fermented fine-divided waste from a fermentation vessel to a vaporization and dehydration vessel to perform to a pre-evaporation step to evaporate fermentation inhibitors such as excess volatile inhibiting compounds, such as ethanol, lactic acid and acetic acid, which inhibits fermentation in the fermentation vessel off from fermented fine-divided waste with the vaporization and dehydrating vessel, and comprise a feeding step for after said pre-evaporation step feeding back partly evaporated fermented fine-divided waste that has a reduced amount of fermentation inhibitors from the vaporization and dehydration vessel to the fermentation vessel for further or additional fermentation of the partly evaporated fermented fine-divided waste, resulting in higher yield and fermentation rate.
Said vaporization and dehydrating means comprises preferably, but not necessarily, mixing means for mixing or moving said fermented fine-divided waste during an evaporation step for at least partly separating by evaporation said mixture of ethanol and water from said fermented fine-divided waste and during a dehydrating step for dehydrating said fermented fine-divided waste to produce dry matter of the fermented fine-divided waste. Said vaporization and dehydrating means can for example comprise a rotary dryer.
In one embodiment of the invention the apparatus comprises a combined hydrolyzing and fermentation and vaporization and dehydration vessel comprising a crusher. In this preferred embodiment the combined hydrolyzing and fermentation and vaporization and dehydration vessel comprising the crusher is preferably sealed in such a way that substantially all vapor separated i.e. vaporized from the fermented fine-divided water is discharged from the combined hydrolyzing and fermentation and vaporization and dehydration vessel through the first discharging means. This preferred embodiment of the invention is especially suitable for small-scale production of ethanol and solid biofuel in the form of dry matter.
In another embodiment of the invention the apparatus comprises a separate crusher, a separate hydrolyzing vessel, a separate fermentation vessel and a separate vaporization and dehydration vessel comprising a rotary dryer. In this preferred embodiment the separate vaporization and dehydration vessel comprising the rotary dryer is preferably sealed in such a way that substantially all vapor separated i.e. vaporized from the fermented fine-divided water containing mixture of ethanol and water is discharged from the separate vaporization and dehydration vessel through the first discharging means and thereafter fed to a concentration means for producing a concentrated mixture of ethanol and water. The vapor is preferably, but not necessarily, filtrated or in a corresponding manner purified prior to feeding the vapor discharged from said first discharging means of said separate vaporization and dehydration vessel to said concentration means. This preferred embodiment of the invention is especially suitable for large-scale production of ethanol and solid biofuel in the form of dry matter.
In a preferred embodiment of the invention the saccharification step is performed without adding water or other liquids to the fine-divided waste, provided that the liquid content of the waste for example the liquid content of the municipal biodegradable waste is sufficient for the saccharification step. In many cases, it is normally possible to produce—with a method according to the invention—a mixture of ethanol and water without adding water or any other liquids to the waste. At least the liquid percentage of municipal biodegradable waste between 70 and 75 has been found to be sufficient and makes additional adding of liquids unnecessary.
Advantages:Possible to produce both liquid biofuel and solid biofuel from waste with one and the same apparatus for example with a method and apparatus described and shown in
Dry matter can be used as a solid biofuel for the production of thermal energy to be used in the process or to be used elsewhere. The thermal energy can be utilized in heat exchanges functionally connected to at least one of the hydrolyzing means, the fermentation means and the vaporization and dehydrating means
Process is very simple. For example in the embodiment shown in
With a method and apparatus of the invention a wide range of waste can be processed.
With a method and apparatus of the invention can ethanol be produced from waste containing fermentable sugars or starch and/or cellulose which can be saccharified into fermentable sugars.
In the following the invention will be described in more detail by referring to the figures, of which
The invention relates firstly to an apparatus for processing waste 1 containing fermentable raw materials selected from sugars and raw materials such as starch and cellulose capable of being saccharified into fermentable sugars.
The apparatus is preferably, but not necessarily, configured for processing municipal biodegradable waste 1 containing fermentable raw materials selected from sugars and raw materials such as starch and cellulose capable of being saccharified into fermentable sugars.
The apparatus comprises crushing means 2 for at least partly fine-dividing said waste 1 containing fermentable raw materials selected from sugars and raw materials such as starch and cellulose capable of being saccharified into fermentable sugars to form fine-divided waste 30.
The apparatus can in addition comprise sorting means (not shown in the figures) for removing possible non-fermentable matter such as plastics and bones present in the waste 1 before feeding said waste 1 to said crushing means 2.
Said crushing means 2 is preferably, but not necessarily, configured to also fine-divide possible non-fermentable matter such as plastics and bones present in the waste 1. The preferred particle size in the fine-divided waste 30 is 0.5 to 2 mm.
The apparatus can in addition comprise screening means (not shown in the figures) for screening said fine-divided waste 30 to remove possible non-fermentable matter such as plastics and bones present in the fine-divided waste 30 after fine-dividing said waste.
The apparatus comprises hydrolyzing means 3 for at least partly saccharifying with saccharifying enzymes said fine-divided waste 30 to form saccharified fine-divided waste 31. The saccharifying enzymes break down at least raw materials such as starch and cellulose capable of being saccharified into fermentable sugars present in the fine-divided waste 30 to produce fermentable sugars.
The apparatus comprises fermentation means 4 for at least partly fermenting with ethanol producing microorganisms 23 such as yeast said saccharified fine-divided waste 31 to form fermented fine-divided waste 32 containing a mixture of ethanol and water 25. The micro-organisms such as yeast use fermentable sugars in the saccharified fine-divided waste to produce ethanol i.e. to produce said fermented fine-divided waste 32 containing a mixture of ethanol and water 25.
The apparatus comprises vaporization and dehydrating means 5 for at least partly separating by vaporization said mixture of ethanol and water 25 from said fermented fine-divided waste 32 and for dehydrating said fermented fine-divided waste 32 in order to form at least partly dry matter 24 of said fermented fine-divided waste 32.
Said vaporization and dehydrating means 5 can be divided into a separate vaporization means 51 for at least partly separating by vaporization said mixture of ethanol and water 25 in said fermented fine-divided waste 32 and a separate dehydrating means 52 for dehydrating fermented fine-divided waste 32 after the fermented fine-divided waste 32 has been treated in said separate vaporization means 51 for at least partly separating by vaporization said mixture of ethanol and water 25 from said fermented fine-divided waste 32. Such embodiments are shown in
Said vaporization and dehydrating means 5 comprises preferably mixing means 43 for mixing or otherwise moving said fermented fine-divided waste 32 in said vaporization and dehydrating means 5.
The vaporization and dehydrating means 5 comprises preferably a drum dryer or a flash dryer.
The vaporization and dehydrating means 5 can for example comprise a dryer apparatus of the type disclosed in publication WO/2006/024696.
The apparatus comprises first discharging means 6 for discharging said vaporized mixture of ethanol and water 25 from said vaporization and dehydrating means 5.
The apparatus comprises second discharging means 7 for discharging said dry matter 24 from said vaporization and dehydrating means 5. The apparatus may comprise conduit means (not marked with a reference numeral) for feeding partly dehydrated fermented fine-divided waste 46 from said vaporization and dehydrating means 5 back to at least of the following: said crushing means 2, said hydrolyzing means 3, and said fermentation means 4.
The apparatus may comprise a solid matter separator means 53 that is arranged downstream of the fermentation means 4 and upstream of the vaporization and dehydration means 5. The apparatuses illustrated in
Said hydrolyzing means 3 comprises in a first preferred embodiment of the apparatus of the invention shown in
In this first preferred embodiment of the invention said crushing means 2 is a crusher 9 arranged in said separate hydrolyzing vessel 8. In this preferred embodiment of the invention said fermentation means 4 comprises a separate fermentation vessel 10 for fermenting with ethanol producing microorganisms 23 such as yeast said saccharified fine-divided waste 31 to form fermented fine-divided waste 32 containing a mixture of ethanol and water 25.
In this first preferred embodiment of the invention said vaporization and dehydrating means 5 comprises a separate vaporization and dehydration vessel 11 for at least partly separating by vaporization said mixture of ethanol and water 25 from said fermented fine-divided waste 32 and for dehydrating said fermented fine-divided waste 32 to form dry matter 24 of said fermented fine-divided waste 32. The separate vaporization and dehydration vessel 11 may, as shown in the ninth embodiment shown in
The apparatus shown in
The apparatus shown in
The apparatus shown in
The apparatus may as in the thirteenth embodiment shown in
The apparatus comprises in a second preferred embodiment of the apparatus of the invention shown in
In this second preferred embodiment of the invention said crushing means 2 is a crusher 9 arranged in said separate hydrolyzing vessel 8.
Said apparatus comprises in
In this second preferred embodiment of the invention shown in
The apparatus shown in
The apparatus shown in
Said hydrolyzing means 3 and said fermentation means 4 comprises in a third preferred embodiment of the apparatus of the invention shown in
In this third preferred embodiment of the invention said crushing means 2 is a crusher 9 arranged in said combined hydrolyzing and fermentation vessel 13.
Said vaporization and dehydrating means 5 comprises in this third preferred embodiment of the invention a separate vaporization and dehydration vessel 11 for at least partly separating by vaporization said mixture of ethanol and water 25 from said fermented fine-divided waste 32 and for dehydrating said fermented fine-divided waste 32 to form dry matter 24 of said fermented fine-divided waste 32. The separate vaporization and dehydration vessel 11 may, as shown in the tenth embodiment shown in
The apparatus shown in
The apparatus shown in
The apparatus may as in the fourteenth embodiment shown in
Said hydrolyzing means 3 and said fermentation means 4 and said vaporization and dehydrating means 5 comprise in a fourth preferred embodiment of the apparatus of the invention shown in
In this fourth preferred embodiment of the invention said crushing means 2 is a crusher 9 arranged in said combined hydrolyzing and fermentation and vaporization and dehydration vessel 14.
In a fifth preferred embodiment of the apparatus of the invention shown in
In this fifth preferred embodiment of the invention said hydrolyzing means 3 comprises a separate hydrolyzing vessel 8 saccharifying with saccharifying enzymes said fine-divided waste 30 to form saccharified fine-divided waste 31.
In this fifth preferred embodiment of the invention said fermentation means 4 comprises a separate fermentation vessel 10 for fermenting with ethanol-producing microorganisms 23 such as yeast or fermenting microorganisms said saccharified fine-divided waste 31 to form fermented fine-divided waste 32 containing a mixture of ethanol and water 25.
In this fifth preferred embodiment of the invention said vaporization and dehydrating means 5 comprises a separate vaporization and dehydration vessel 11 for at least partly separating by vaporization said mixture of ethanol and water 25 from said fermented fine-divided waste 32 and for dehydrating said fermented fine-divided waste 32 to form dry matter 24 of said fermented fine-divided waste 32. The separate vaporization and dehydration vessel 11 may, as shown in the eleventh embodiment shown in
The apparatus shown in
The apparatus shown in
The apparatus shown in
The apparatus shown in
The apparatus may as in the fifteenth embodiment shown in
In a sixth preferred embodiment of the apparatus of the invention shown in
In this sixth preferred embodiment of the invention said hydrolyzing means 3 and said fermentation means 4 comprises a combined hydrolyzing and fermentation vessel 13 for firstly saccharifying with saccharifying enzymes said fine-divided waste to form saccharified fine-divided waste 31 and thereafter for fermenting with ethanol-producing microorganisms 23 such as yeast or fermenting microorganisms said saccharified fine-divided waste 31 to form fermented fine-divided waste 32 containing mixture of ethanol and water 25.
In this sixth preferred embodiment of the invention said vaporization and dehydrating means 5 comprises a separate vaporization and dehydration vessel 11 for at least partly separating by vaporization said mixture of ethanol and water 25 from said fermented fine-divided waste 32 and for dehydrating said fermented fine-divided waste 32 to form dry matter 24 of said fermented fine-divided waste 32. The separate vaporization and dehydration vessel 11 may, as shown in the twelfth embodiment shown in
The apparatus shown in
The apparatus shown in
The apparatus shown in
In a seventh preferred embodiment of the apparatus of the invention shown in
In this seventh preferred embodiment of the invention said hydrolyzing means 3 comprises a separate hydrolyzing vessel 8 for saccharifying with saccharifying enzymes said fine-divided waste 30 to form saccharified fine-divided waste 31.
In this seventh preferred embodiment of the invention said fermentation means 4 and said vaporization and dehydrating means 5 comprise a combined fermentation and vaporization and dehydration vessel 12 for firstly fermenting with ethanol-producing microorganisms 23 said saccharified fine-divided waste 31 to form fermented fine-divided waste 32 containing mixture of ethanol and water 25 and for thereafter at least partly separation by vaporization said mixture of ethanol and water 25 from said fermented fine-divided waste 32 and for dehydrating said fermented fine-divided waste 32 to form dry matter 24 of said fermented fine-divided waste 32.
The apparatus shown in
The apparatus shown in
The apparatus shown in
In an eight preferred embodiment of the apparatus of the invention shown in
Said hydrolyzing means 3 and said fermentation means 4 and said vaporization and dehydrating means 5 comprise in this eight preferred embodiment of the invention shown in
The apparatus shown in
Said crushing means 2 is preferably configured to finely divide said municipal biodegradable waste 1 comprising at least one of starch and cellulose to fine-divided waste 30 having a particle size of 0.5 to 2 mm, for example about 1 mm.
Said hydrolyzing means 3 includes preferably, but not necessarily, means for adding saccharifying enzymes 16 to said fine-divided waste 30, the saccharifying enzymes 20 being selected from amylases, cellulases, and hemicellulases. Amylases are hydrolytic enzymes, which hydrolyze starch and include α-amylases, β-amylases and glycoamylases. Cellulases hydrolyzing cellulose include endoglucanases, cellobiohydrolases and β-glucosidases. Enzymes degrading hemicellulose include xylanases and mannanases and side-chain cleaving enzymes, such as α-glucuronidases, acetyl xylan esterases, α-arabinofuranosidases and α-galactosidases. After combined action of these enzymes, the starch, cellulose and hemicellulose polymers are hydrolyzed into monomeric hexose and pentose sugars, which then may be fermented by ethanol-producing microorganisms. Different enzyme mixtures for hydrolyzing starch, cellulose and hemicellulose polymers are commercially available.
Said means for adding saccharifying enzymes 16 to said biodegradable waste comprising at least one of starch and cellulose can be arranged in combination with a separate hydrolyzing vessel 8 as shown in
Said hydrolyzing means 3 includes preferably, but not necessarily, means for adding other hydrolyzing enzymes 44 to said fine-divided waste 30, such hydrolyzing enzymes 45 being selected from proteases and pectinases.
Said hydrolyzing means 3 includes preferably, but not necessarily, means for adding water 18 to said biodegradable waste comprising at least one of starch and cellulose.
Said means for adding water to said biodegradable waste comprising at least one of starch and cellulose can be arranged in combination with a separate hydrolyzing vessel 8 as shown in
Said hydrolyzing means 3 includes preferably, but not necessarily, means for adding acid 17 to said fine-divided waste 30, the acid 21 being selected from organic acid and mineral acid, such as sulfuric acid.
Said means for adding acid 17 to said biodegradable waste comprising at least one of starch and cellulose can be arranged in combination with a separate hydrolyzing vessel 8 as shown in
Said fermentation means 4 includes preferably, but not necessarily, means for adding an ethanol producing or fermenting microorganism to said saccharified fine-divided waste 31.
Said means for adding an ethanol producing or fermenting microorganism 19 to said saccharified fine-divided waste 31 can be arranged in combination with a separate fermentation vessel 10 as shown in
In the preferred embodiments of the invention shown in the figures, the apparatus comprises a concentration means 26 for concentrating said mixture of ethanol and water 25.
Said concentration means 26 comprises in the figures an evaporator 27, which preferably is a falling film evaporator or a flash evaporator. A boiler 28 is functionally connected to the evaporator 27. The boiler 28 is adapted to receive a mixture of ethanol and water 25 from the vaporization and dehydrating means 5 and to evaporate a mixture of ethanol and water 25 prior to feeding a mixture of ethanol and water 25 into the evaporator. The apparatus comprises also conduit means (not marked with a reference numeral) for leading condensed evaporate 37 from the evaporator 27 to the boiler 28 to evaporate the condensed evaporate and conduit means (not marked with a reference numeral) for leading heated evaporate 36 from the boiler 28 back to the evaporator 27.
The apparatus shown in the figures comprises conduit means (not marked with a reference numeral) for feeding a residual bottom stream of distilled water 29 from the evaporator 27 to the hydrolyzing means 2. Alternatively or in addition distilled water 35 can be removed from the process as shown with a dotted arrow in the figures.
The apparatus shown in the figures comprises conduit means (not marked with a reference numeral) for feeding concentrated mixture of ethanol and water 39 from the evaporator 27 for example to a storage tank (not shown in the figures).
In the preferred embodiments of the invention shown in the figures the apparatus comprises a burning means 40 for receiving dry matter 24 and for producing of thermal energy by burning said dry matter 24, and in that the thermal energy is at least partly used in the apparatus.
In the first and fifth embodiments of the invention shown in
In the second and sixth embodiments of the invention shown in
In the third and seventh embodiments of the invention shown in
In the fourth and eighth embodiments of the invention shown in
In the embodiments of the invention shown in the figures thermal energy from said burning means can also be fed to the boiler 28.
The invention also relates to a method for processing waste 1 containing fermentable raw materials selected from sugars and raw materials such as starch and cellulose capable of being saccharified into fermentable sugars.
The waste 1 is preferably, but not necessarily, municipal biodegradable waste containing fermentable raw materials selected from sugars and raw materials such as starch and cellulose capable of being saccharified into fermentable sugars.
The method comprises a crushing step for at least partly fine-dividing said waste 1 containing fermentable raw materials selected from sugars and raw materials such as starch and cellulose capable of being saccharified into fermentable sugars to form fine-divided waste 30.
A sorting step for removing non-fermentable matter such as plastics and bones from the waste 1 can preferably, but not necessarily, be performed before said crushing step.
Said crushing step is preferably, but not necessarily, performed with a crushing means 2 configured to also fine-divide possible non-fermentable matter such as plastics and bones present in the waste 1.
The method can in addition comprise a screening step for screening said fine-divided waste 30 to remove possible non-fermentable matter such as plastics and bones present in the fine-divided waste 30 after said crushing step for at least partly fine-dividing said waste 1.
The method comprises a saccharification step for at least partly saccharifying with enzymes 20 said fine-divided waste 30 to form saccharified fine-divided waste 31. In this saccharification step the saccharifying enzymes break down at least raw materials such as starch and cellulose capable of being saccharified into fermentable sugars present in the fine-divided waste 30 to produce fermentable sugars.
The method comprises a fermentation step for at least partly fermenting with an ethanol-producing microorganism 23 said saccharified fine-divided waste 31 to form fermented fine-divided waste 32 containing a mixture of ethanol and water 25. In this fermentation step the ethanol-producing microorganisms use fermentable sugars in the saccharified fine-divided waste to produce ethanol i.e. to produce said fermented fine-divided waste 32 containing a mixture of ethanol and water 25.
The method comprises a vaporization step for at least partly separate by vaporization said mixture of ethanol and water 25 from said fermented fine-divided waste 32 that can be performed in a vaporization and dehydration means 5. Alternatively, the method comprises a vaporization step for at least partly separate by vaporization said mixture of ethanol and water 25 from said fermented fine-divided waste 32 in a separate vaporization means 51.
The method comprises a dehydrating step for at least partly dehydrating said fermented fine-divided waste 32 to form dry matter 24 of said fermented fine-divided waste 32 that can be performed in a vaporization and dehydration means 5. Alternatively, the method comprises a vaporization step for at least partly dehydrating said fermented fine-divided waste 32 to form dry matter 24 of said fermented fine-divided waste 32 in a separate dehydration means 52.
The method comprises an ethanol mixture collecting step for discharging and collecting said vaporized mixture of ethanol and water 25 from said vaporization and dehydrating means 5 or from said separate vaporization means 51.
The method comprises a dry matter 24 collecting step for collecting said dry matter 24 from said vaporization and dehydrating means 5 or from said separate dehydration means 52.
Said fermented fine-divided waste 32 is preferably, but not necessarily, mixing and/or moving said fermented fine-divided waste 32 during at least one of the vaporization steps and the dehydrating steps. Said mixing or moving can for example be performed by means of a rotary dryer.
The fermentation step of the method of the invention may comprise a pre-vaporization step for removing fermentation inhibitors from fermented fine-divided waste containing fermentation inhibitors which includes feeding step for firstly feeding fermented fine-divided waste containing fermentation inhibitors from a fermentation vessel to a vaporization and dehydration vessel to perform to a pre-evaporation step to evaporate fermentation inhibitors such as excess volatile inhibiting compounds, such as ethanol, lactic acid and acetic acid, which inhibits fermentation in the fermentation vessel off from fermented fine-divided waste with the vaporization and dehydrating vessel, and comprise a feeding step for after said pre-evaporation step feeding back partly evaporated fermented fine-divided waste that has a reduced amount of fermentation inhibitors from the vaporization and dehydration vessel to the fermentation vessel for further or additional fermentation of the partly evaporated fermented fine-divided waste, resulting in higher yield and fermentation rate. In other words, the fermentation step of the method of the invention may for example comprise a pre-vaporization step for removing fermentation inhibitors from fermented fine-divided waste containing fermentation inhibitors by vaporization fermentation inhibitors from said fermented fine-divided waste containing fermentation inhibitors.
The saccharification step can take 1-24 hours depending for example on the amount of fine-divided waste
The fermentation step can take 24-72 hours and be performed at a temperature between about 20° C. and about 40° C. depending for example on the ethanol-producing microorganism.
The method of the invention may comprise a solid matter separation step that is performed after the fermentation step and before the vaporization step and that us performed in a solid matter separator means 53.
In a first preferred embodiment of the method of the invention shown in
In this first preferred embodiment of the invention said crushing step includes crushing said waste 1 with a crusher 9 to form said fine-divided waste 30 with a crusher 9, which is arranged in said separate hydrolyzing vessel 8.
This first preferred embodiment of the invention includes a saccharification step performed in the separate hydrolyzing vessel 8 for saccharifying with saccharifying enzymes said fine-divided waste 30 to form saccharified fine-divided waste 31.
This first preferred embodiment of the invention includes a feeding step for feeding saccharified fine-divided waste 31 from said separate hydrolyzing vessel 8 into a separate fermentation vessel 10.
This first preferred embodiment of the invention includes a fermentation step performed in the separate fermentation vessel 10 for at least partly fermenting with an ethanol-producing microorganism said saccharified fine-divided waste 31 to obtain fermented fine-divided waste 32 containing mixture of ethanol and water 25.
This first preferred embodiment of the invention includes a feeding step for feeding fermented fine-divided waste 32 containing a mixture of ethanol and water 25 from said separate fermentation vessel 10 into a separate vaporization and dehydration vessel 11.
This first preferred embodiment of the invention includes a vaporization step and a dehydration step performed in the separate vaporization and dehydration vessel 11 for at least partly separating by vaporization said mixture of ethanol and water 25 from said fermented fine-divided waste 32 and for dehydrating said fermented fine-divided waste 32 to form dry matter 24 of said fermented fine-divided waste 32.
This first preferred embodiment of the invention includes an ethanol mixture collecting step for discharging and collecting said vaporized mixture of ethanol and water 25 from said separate vaporization and dehydration vessel 11.
This first preferred embodiment of the invention includes a dry matter 24 collecting step for discharging and collecting said dry matter 24 from said separate vaporization and dehydration vessel 11.
The fermentation step of this first preferred embodiment of the method of the invention illustrated in
In the same manner as the first preferred embodiment of the method of the invention the ninth preferred embodiment of the method of the invention may comprises a pre-evaporation step for removing fermentation inhibitors from fermented fine-divided waste containing fermentation inhibitors 47. In the ninth preferred embodiment of the method of the invention fermentation inhibitors are removed by feeding fermented fine-divided waste containing fermentation inhibitors 47 into the separate vaporization vessel 48 and by using the separate vaporization vessel 48 for vaporizing fermentation inhibitors off the fermented fine-divided waste containing fermentation inhibitors 47.
The method may as in the thirteenth embodiment shown in
In a second preferred embodiment of the method of the invention shown in
In this second preferred embodiment of the invention said crushing step includes crushing said waste 1 with a crusher 9 to form fine-divided waste 30 with a crusher 9, which is arranged in said separate hydrolyzing vessel 8.
This second preferred embodiment of the invention includes a saccharification step performed in the separate hydrolyzing vessel 8 for saccharifying with saccharifying enzymes said fine-divided waste 30 to form saccharified fine-divided waste 31.
This first preferred embodiment of the invention includes a feeding step for feeding saccharified fine-divided waste 31 from said separate hydrolyzing vessel 8 into a combined fermentation and vaporization and dehydration vessel 12.
In this second preferred embodiment of the invention shown in
In the second preferred embodiment of the invention shown in
This second preferred embodiment of the invention includes an ethanol mixture collecting step for discharging and collecting said vaporized mixture of ethanol and water 25 from said combined fermentation and vaporization and dehydration vessel 12.
This second preferred embodiment of the invention includes a dry matter 24 collecting step for discharging and collecting said dry matter 24 from said combined fermentation and vaporization and dehydration vessel 12.
The fermentation step of this second preferred embodiment of the method of the invention illustrated in
In a third preferred embodiment of the method of the invention shown in
In this third preferred embodiment of the invention said crushing step includes crushing said waste 1 with a crusher 9 to form fine-divided waste 30 with a crusher 9, which is arranged in said combined hydrolyzing and fermentation vessel 13.
This third preferred embodiment of the method of the invention includes firstly a saccharification step performed in said combined hydrolyzing and fermentation vessel 13 for saccharifying with saccharifying enzymes said fine-divided waste 30 to form saccharified fine-divided waste 31. This third preferred embodiment of the invention includes thereafter a fermentation step in the combined hydrolyzing and fermentation vessel 13 for at least partly fermenting with an ethanol-producing microorganism said saccharified fine-divided waste 31 to obtain fermented fine-divided waste 32 containing mixture of ethanol and water 25 in the combined hydrolyzing and fermentation vessel 13.
This third preferred embodiment of the method of the invention includes a feeding step for feeding fermented fine-divided waste 32 containing mixture of ethanol and water 25 from said combined hydrolyzing and fermentation vessel 13 into a separate vaporization and dehydration vessel 11.
In the third preferred embodiment of the method of the invention shown in
This third preferred embodiment of the method of the invention includes an ethanol mixture collecting step for discharging and collecting said vaporized mixture of ethanol and water 25 from said separate vaporization and dehydration vessel 11.
This third preferred embodiment of the method of the invention includes a dry matter 24 collecting step for discharging and collecting said dry matter 24 from said separate vaporization and dehydration vessel 11.
The fermentation step of this third preferred embodiment of the method of the invention may as illustrated in
In the same manner as the third preferred embodiment of the method of the invention the tenth preferred embodiment of the method of the invention may comprises a pre-evaporation step for removing fermentation inhibitors from fermented fine-divided waste containing fermentation inhibitors 47. In the tenth preferred embodiment of the method of the invention fermentation inhibitors are removed by feeding fermented fine-divided waste containing fermentation inhibitors 47 into the separate vaporization vessel 48 and by using the separate vaporization vessel 48 for vaporizing fermentation inhibitors off the fermented fine-divided waste containing fermentation inhibitors 47.
The method may as in the fourteenth embodiment shown in
In a fourth preferred embodiment of the method of the invention the method shown in
In this fourth preferred embodiment of the method of the invention said crushing step includes crushing said waste 1 with a crusher 9 to form fine-divided waste 30 with a crusher 9, which is arranged in said combined hydrolyzing and fermentation and vaporization and dehydration vessel 14.
This fourth preferred embodiment of the method of the invention includes firstly a saccharification step performed in said combined hydrolyzing and fermentation and vaporization and dehydration vessel 14 for saccharifying with saccharifying enzymes said fine-divided waste 30 to form saccharified fine-divided waste 31.
This fourth preferred embodiment of the method of the invention includes thereafter a fermentation step performed in said combined hydrolyzing and fermentation and vaporization and dehydration vessel 14 for at least partly fermenting with an ethanol-producing microorganism said saccharified fine-divided waste 31 to obtain fermented fine-divided waste 32 containing mixture of ethanol and water 25 in the combined hydrolyzing and fermentation and vaporization and dehydration vessel 14.
This fourth preferred embodiment of the method of the invention includes thereafter a dehydration step performed in said combined hydrolyzing and fermentation and vaporization and dehydration vessel 14 for at least partly separating by vaporization said mixture of ethanol and water 25 from said fermented fine-divided waste 32 and for dehydrating said fermented fine-divided waste 32 to form dry matter 24 of said fermented fine-divided waste 32 in said combined hydrolyzing and fermentation and vaporization and dehydration vessel 14.
This fourth preferred embodiment of the method of the invention includes an ethanol mixture collecting step for discharging and collecting said vaporized mixture of ethanol and water 25 from said combined hydrolyzing and fermentation and vaporization and dehydration vessel 14.
This fourth preferred embodiment of the method of the invention includes a dry matter 24 collecting step for discharging and collecting said dry matter 24 from said combined hydrolyzing and fermentation and vaporization and dehydration vessel 14.
The fermentation step of this fourth preferred embodiment of the method of the invention may include a pre-vaporization step for removing fermentation inhibitors from fermented fine-divided waste containing fermentation inhibitors 47. This pre-vaporization step includes pre-vaporization step includes a pre-evaporation step for separating in said combined hydrolyzing and fermentation and vaporization and dehydration vessel 14 by vaporization fermentation inhibitors from said fine-divided waste containing fermentation inhibitors 47 whereby partly dehydrated fermented fine-divided waste 46 is obtained. This pre-vaporization step includes by continuing said fermentation step in said combined hydrolyzing and fermentation and vaporization and dehydration vessel 14 after said pre-vaporization step by at least partly fermenting with ethanol-producing microorganism 23 said partly dehydrated fermented fine-divided waste 46 in said combined hydrolyzing and fermentation and vaporization and dehydration vessel 14.
In a fifth preferred embodiment of the method of the invention shown in
This fifth preferred embodiment of the method of the invention includes a crushing step including crushing municipal biodegradable waste 1 with said separate crusher 15 to form fine-divided waste 30.
This fifth preferred embodiment of the invention includes a feeding step for feeding said fine-divided waste 30 from said separate crusher 15 into a separate hydrolyzing vessel 8.
This fifth preferred embodiment of the method of the invention includes a saccharification step performed in said separate hydrolyzing vessel 8 for at least partly saccharifying with saccharifying enzymes said fine-divided waste 30 to form saccharified fine-divided waste 31.
This fifth preferred embodiment of the invention includes a feeding step for feeding said saccharified fine-divided waste 31 from said separate hydrolyzing vessel 8 into a separate fermentation vessel 10.
This fifth preferred embodiment of the invention includes a fermentation step performed in said separate fermentation vessel 10 for at least partly fermenting with an ethanol-producing microorganism said saccharified fine-divided waste 31 to obtain fermented fine-divided waste 32 containing mixture of ethanol and water 25 in said separate fermentation vessel 10.
This fifth preferred embodiment of the invention includes a feeding step for feeding said fermented fine-divided waste 32 containing a mixture of ethanol and water 25 from said separate fermentation vessel 10 into a separate vaporization and dehydration vessel 11.
This fifth preferred embodiment of the invention includes a vaporization and dehydrating step performed in said separate vaporization and dehydration vessel 11 for at least partly separating by vaporization mixture of ethanol and water 25 from said fermented fine-divided waste 32 and for dehydrating said fermented fine-divided waste 32 to form dry matter 24 of said fermented fine-divided waste 32.
This fifth preferred embodiment of the method of the invention includes an ethanol mixture collecting step for discharging and collecting said vaporized mixture of ethanol and water 25 from said separate vaporization and dehydration vessel 11.
This fifth preferred embodiment of the method of the invention includes a dry matter 24 collecting step for discharging and collecting said dry matter 24 from said separate vaporization and dehydration vessel 11.
The fermentation step of this fifth preferred embodiment of the method of the invention illustrated in
In the same manner as the first preferred embodiment of the method of the invention the eleventh preferred embodiment of the method of the invention may comprises a pre-evaporation step for removing fermentation inhibitors from fermented fine-divided waste containing fermentation inhibitors 47. In the eleventh preferred embodiment of the method of the invention fermentation inhibitors are removed by feeding fermented fine-divided waste containing fermentation inhibitors 47 into the separate vaporization vessel 48 and by using the separate vaporization vessel 48 for vaporizing fermentation inhibitors off the fermented fine-divided waste containing fermentation inhibitors 47.
The method may as in the fifteenth embodiment shown in
In a sixth preferred embodiment of the method of the invention shown in
This sixth preferred embodiment of the method of the invention includes a crushing step including crushing municipal biodegradable waste 1 with said separate crusher 15 to form fine-divided waste 30.
This sixth preferred embodiment of the method of the invention includes a feeding step for feeding said fine-divided waste 30 from said separate crusher 15 into a combined hydrolyzing and fermentation vessel 13.
This sixth preferred embodiment of the method of the invention includes firstly a saccharification step performed in said combined hydrolyzing and fermentation vessel 13 for at least partly saccharifying with saccharifying enzymes said fine-divided waste 30 to form saccharified fine-divided waste 31 in said combined hydrolyzing and fermentation vessel 13. This sixth preferred embodiment of the method of the invention includes thereafter a fermentation step performed in said combined hydrolyzing and fermentation vessel 13 for at least partly fermenting with ethanol-producing microorganism said saccharified fine-divided waste 31 to obtain fermented fine-divided waste 32 containing mixture of ethanol and water 25 in said combined hydrolyzing and fermentation vessel 13.
This sixth preferred embodiment of the invention includes a feeding step for feeding said fermented fine-divided waste 32 containing a mixture of ethanol and water 25 from said combined hydrolyzing and fermentation vessel 13 into a separate vaporization and dehydration vessel 11.
This sixth preferred embodiment of the invention includes a vaporization and dehydrating step performed in said separate vaporization and dehydration vessel 11 for at least partly separating by vaporization mixture of ethanol and water 25 from said fermented fine-divided waste 32 and for dehydrating said fermented fine-divided waste 32 to form dry matter 24 of said fermented fine-divided waste 32.
This sixth preferred embodiment of the method of the invention includes an ethanol mixture collecting step for discharging and collecting said vaporized mixture of ethanol and water 25 from said separate vaporization and dehydration vessel 11.
This sixth preferred embodiment of the method of the invention includes a dry matter 24 collecting step for discharging and collecting said dry matter 24 from said separate vaporization and dehydration vessel 11.
The fermentation step of this sixth preferred embodiment of the method of the invention may as illustrated in
In the same manner as the first preferred embodiment of the method of the invention the twelfth preferred embodiment of the method of the invention may comprises a pre-evaporation step for removing fermentation inhibitors from fermented fine-divided waste containing fermentation inhibitors 47. In the twelfth preferred embodiment of the method of the invention fermentation inhibitors are removed by feeding fermented fine-divided waste containing fermentation inhibitors 47 into the separate vaporization vessel 48 and by using the separate vaporization vessel 48 for vaporizing fermentation inhibitors off the fermented fine-divided waste containing fermentation inhibitors 47.
The method may as in the sixteenth embodiment shown in
In a seventh preferred embodiment of the method of the invention shown in
This seventh preferred embodiment of the method of the invention includes a crushing step including crushing municipal biodegradable waste 1 with said separate crusher 15 to form fine-divided waste 30.
This seventh preferred embodiment of the invention includes a feeding step for feeding said fine-divided waste 30 from said separate crusher 15 into a separate hydrolyzing vessel 8.
This seventh preferred embodiment of the method of the invention includes a saccharification step performed in said separate hydrolyzing vessel 8 for at least partly saccharifying with saccharifying enzymes said fine-divided waste 30 to form saccharified fine-divided waste 31.
This seventh preferred embodiment of the invention includes a feeding step for feeding said saccharified fine-divided waste 31 from said separate hydrolyzing vessel 8 into a combined fermentation and vaporization and dehydration vessel 12.
This seventh preferred embodiment of the method of the invention includes firstly a fermentation step performed in said combined fermentation and vaporization and dehydration vessel 12 for at least partly fermenting with an ethanol-producing microorganism said saccharified fine-divided waste 31 to obtain fermented fine-divided waste 32 containing a mixture of ethanol and water 25 in said combined fermentation and vaporization and dehydration vessel 12.
This seventh preferred embodiment of the invention includes thereafter a vaporization and dehydrating step performed in said combined fermentation and vaporization and dehydration vessel 12 for at least partly separating by vaporization of said mixture of ethanol and water 25 from said fermented fine-divided waste 32 and for dehydrating said fermented fine-divided waste 32 to form dry matter 24 of said fermented fine-divided waste 32.
This seventh preferred embodiment of the method of the invention includes an ethanol mixture collecting step for discharging and collecting said vaporized mixture of ethanol and water 25 from said combined fermentation and vaporization and dehydration vessel 12.
This seventh preferred embodiment of the method of the invention includes a dry matter 24 collecting step for discharging and collecting said dry matter 24 from said combined fermentation and vaporization and dehydration vessel 12.
The fermentation step of this seventh preferred embodiment of the method of the invention illustrated in
In an eighth preferred embodiment of the method of the invention shown in
This eighth preferred embodiment of the method of the invention includes a crushing step including crushing municipal biodegradable waste 1 with said separate crusher 15 to form fine-divided waste 30.
This eighth preferred embodiment of the invention includes a feeding step for feeding said fine-divided waste 30 from said separate crusher 15 into a combined hydrolyzing and fermentation and vaporization and dehydration vessel 14.
This eighth preferred embodiment of the method of the invention includes firstly a saccharification step performed in said combined hydrolyzing and fermentation and vaporization and dehydration vessel 14 for saccharifying with saccharifying enzymes said fine-divided waste 30 to form saccharified fine-divided waste 31.
This eighth preferred embodiment of the method of the invention includes thereafter a fermentation step performed in said combined hydrolyzing and fermentation and vaporization and dehydration vessel 14 for at least partly fermenting with an ethanol-producing microorganism said saccharified fine-divided waste 31 to obtain fermented fine-divided waste 32 containing mixture of ethanol and water 25 in the combined hydrolyzing and fermentation and vaporization and dehydration vessel 14.
This eighth preferred embodiment of the method of the invention includes thereafter a vaporization and dehydrating step performed in said combined hydrolyzing and fermentation and vaporization and dehydration vessel 14 for at least partly separating by vaporization said mixture of ethanol and water 25 from said fermented fine-divided waste 32 and for dehydrating said fermented fine-divided waste 32 to form dry matter 24 of said fermented fine-divided waste 32 in said combined hydrolyzing and fermentation and vaporization and dehydration vessel 14.
This eighth preferred embodiment of the method of the invention includes an ethanol mixture collecting step for discharging and collecting said vaporized mixture of ethanol and water 25 from said combined hydrolyzing and fermentation and vaporization and dehydration vessel 14.
This eighth preferred embodiment of the method of the invention includes a dry matter 24 collecting step for discharging and collecting said dry matter 24 from said combined hydrolyzing and fermentation and vaporization and dehydration vessel 14.
The fermentation step of this eight preferred embodiment of the method of the invention may include a pre-vaporization step for removing fermentation inhibitors from fermented fine-divided waste containing fermentation inhibitors 47. This pre-vaporization step includes pre-vaporization step includes a pre-evaporation step for separating in said combined hydrolyzing and fermentation and vaporization and dehydration vessel 14 by vaporization fermentation inhibitors from said fine-divided waste containing fermentation inhibitors 47 whereby partly dehydrated fermented fine-divided waste 46 is obtained. This pre-vaporization step includes by continuing said fermentation step in said combined hydrolyzing and fermentation and vaporization and dehydration vessel 14 after said pre-vaporization step by at least partly fermenting with ethanol-producing microorganism 23 said partly dehydrated fermented fine-divided waste 46 in said combined hydrolyzing and fermentation and vaporization and dehydration vessel 14.
In a preferred embodiment of the invention said crushing step includes fine dividing of said municipal biodegradable waste 1 into particles having a size of about 0.5 to about 2 mm, preferably about 1 to about 1.5 mm
In a preferred embodiment of the invention said hydrolyzing step including a feeding step for adding acid 21 to said fine-divides waste 30, the acid 21 being selected from organic acid and mineral acid, such as sulfuric acid.
In a preferred embodiment of the invention said hydrolyzing step including a feeding step for adding saccharifying enzymes 20 to said fine-divided waste 30, the saccharifying enzymes 20 being selected from amylases, cellulases, and hemicellulases. Amylases are hydrolytic enzymes, which hydrolyze starch and include α-amylases, β-amylases and glycoamylases. Cellulases hydrolyzing cellulose include endoglucanases, cellobiohydrolases and β-glucosidases. Enzymes degrading hemicellulose include xylanases and mannanases and side-chain cleaving enzymes, such as α-glucuronidases, acetyl xylan esterases, α-arabinofuranosidases and α-galactosidases. After combined action of these enzymes, the starch, cellulose and hemicellulose polymers are hydrolyzed into monomeric hexose and pentose sugars, which then may be fermented by ethanol-producing microorganisms. Different enzyme mixtures for hydrolyzing starch, cellulose and hemicellulose polymers are commercially available.
In a preferred embodiment of the invention said hydrolyzing step including a feeding step for adding other hydrolyzing enzymes 45 to said fine-divided waste 30, the other hydrolyzing enzymes 45 being selected from proteases and pectinases.
In a preferred embodiment of the invention said hydrolyzing step including a feeding step for adding enzymes having both a saccharifying and a hydrolyzing effect to said fine-divided waste 30.
In a preferred embodiment of the invention said hydrolyzing step includes a feeding step for adding water 22 to the biodegradable waste comprising at least one of starch and cellulose.
In a preferred embodiment of the invention said fermentation step includes a feeding step for adding an ethanol-producing microorganism 23 to said saccharified fine-divided waste 31.
In another preferred embodiment of the invention the method includes a burning step for burning said dry matter 24 collected in said dry matter 24 collection step.
In another preferred embodiment of the invention the method includes a concentration step for concentrating said mixture of ethanol and water 25 collected in said ethanol collection step by means of a concentration means 26 for concentrating said mixture of ethanol and water 25.
A pilot scale test was performed with a Drais TurbuDry 250 vacuum dryer (Drais-Werke GmbH, Mannheim, Germany), in other words with a test equipment corresponding to the first preferred embodiment shown in
250 l municipal biodegradable waste was collected for the test. Polymers and bones were removed manually from the municipal biodegradable waste and the weight of the purified municipal biodegradable waste was after this purification 120 kg. The dry matter content of the purified municipal biodegradable waste was measured to 32%.
The purified municipal biodegradable waste (120 kg) was fed into the vacuum dryer and 60 kg water was added to the purified municipal biodegradable waste, which resulted in a dry matter content of 20%.
Thereafter the mixture of purified municipal biodegradable waste and water was fine-divided by means of a crusher arranged in the vacuum dryer.
Liquefaction enzyme (Genencor: Spezyme Fred, dosage 5×0.14% dry matter) was added to the cold mixture and the temperature of the mixture was raised to 75° C. The separator arranged in the vacuum dryer was turned on during the liquefaction and heating to rotate at a speed of 85 rpm.
After 60 minutes the temperature of the mixture was lowered to a fermentation temperature of 32° C. The revolution of the crusher was lowered to 30 rpm during the fermentation. Yeast (Yeast cream, manufacturer Suomen Hiiva, Finland 8 g/l) and saccharifying enzyme (Genencor, USA: Stargen, dosage 0.28% of the dry matter) was added to the cooled mixture. The interior of the vacuum dryer was nitrified to faster achieve an anaerobic state. The temperature was kept at 32° C. during the fermentation, which was let to continue for 44 hours, after which the fermentation was let to continue, but the fermentation was slower.
After this the fermented mixture was dehydrated by carefully lowering the pressure. The vapor was collected in the beginning until the temperature and the pressure were stabilized. The collected vapor was filtrated and the result was 15 kg of 4.2% ethanol. Dehydration of the mixture was continued without collection of vapor until the dry matter percentage of the mixture was 94% and the result was 14 kg dry matter i.e. solid biofuel. The effective caloric value of the solid biofuel was measured to be 18.48 MJ/kg (5.133 MWh/t).
It is apparent to a person skilled in the art that as technology advances, the basic idea of the invention can be implemented in various ways. It is obvious for a person skilled in the art that the number of vessels can be different from the number of vessels shown in the apparatuses of the examples. It is obvious for a person skilled in the art that the apparatuses can comprise several vessels of the same type for example arranged in series. The invention and its embodiments are therefore not restricted to the above examples, but they may vary within the scope of the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 20085477 | May 2008 | FI | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/FI09/50381 | 5/11/2009 | WO | 00 | 4/4/2011 |
